Garry, who was plagued by shin problems during his early career, had the jab last week and is waiting to discover whether it has had the desired effect.
The 27-year-old remains Eddie Howe's main defensive concern, with the Cherries boss keen for his resources to return to full strength ahead of the hectic festive period.
Shaun Cooper (calf), Tim Stephenson (knee) and Mitchell Nelson (ankle) are all on the comeback trail and Howe would like Garry to join them.
Garry, who has been restricted to just one appearance in the past six weeks, sustained multiple stress fractures to both shins when he was at Arsenal in 2003.
Howe told the Daily Echo last night: Ryan has seen a specialist in London a couple of times to try to find out what is causing the pain but we still haven't got to the bottom of it.
He has had an injection, which we're hoping will work, but it will take three to four days to kick in. Hopefully, his symptoms will improve and, if that's the case, we may well try to get him running early this week.
It is an added worry for Ryan because of what happened before and there was no tackle or specific incident that brought it on. Generally, you know where the injury has come from and that can sometimes help relate to the problem.
We will endeavour to get it sorted out as quickly as we can. Ryan is in the best possible hands with the surgeon who dealt with him before.
Discussing Cooper, who has been troubled by problems with both calves in recent weeks, Howe said: He is making good progress and is improving every day. I don't think he is too far away from stepping up his rehab.
Nelson is on the mend after sustaining ankle ligament damage just two games into his loan spell with Eastbourne Borough, while Stephenson is back after hurting the medial ligaments in his knee during a reserve outing in September.
Meanwhile, midfielder Marc Pugh (gashed leg) and goalkeeper Shwan Jalal (fractured eye socket) are both making good progress after becoming casualties of Cherries' 2-2 draw at Orient last month.
Howe added: Marc has had his stitches out and is running again. He does have a wound but it is healing all the time and we're pleased with how he's coming along.
Shwan is also improving. He has been working hard in the gym and, hopefully, we will have him back sooner than was first anticipated.
Midfielder Mark Molesley, sidelined for more than a year with a foot injury, should return to full training once the inclement weather has subsided.